The fabric is light-weight.
The garment label indicates this item is a size 7.
Since this item is vintage, please check the measurements below.

Measurements:
Neck opening 14”
From the nape (center-top back neck seam) to the sleeve edge 22”
Around the cuff/sleeve edge 5”
Across the back (armpit seam to armpit seam) 14 ½"
Length (from the center-top back neck seam/nape to the bottom edge) 15 ½"
Around the bottom 21”